Fuel saver



Oct. 27 1925- w. M. HAYWARD Filed April 26, 1923 @zwaai Ziff Patented Get. 27, 1925.

UNITED STATES WILLIAM M. HAYWARD, OF NATICK. MASSACHUSETTS.

FUEL SAVER.

Application tiled April 26, 1923.

T0 (/Z, 1o/10mi't may Concern Be it known that l, Turrini N. llavwann.,` a citizen of the United States. residing at Natielo in the county ot' Middlesex and State of MassachusettsR have invented new and useful improvements in Fuel Savers, of which the following is a specitication.

This invention relates to fuel savers of that type designed to introduce heated air into the combustion chamber of a furnace or hot water or steam boiler and comprises a construction whereby highly heated air is admitted and directed in films or layers, one close to the surface of the fuel to cause combustion of gases distilled ott by the incandescent body of fuel thereheneath, and one into the upper portion of the combustion chamber, this latter acting to break up and forrn a combustible mixture with the gases thrown off in great quantities from fresh fuel just after its application to the fire, this combustible mixture being ignited by the flame from the lower tifuae layer which acts as a pilot light.

By the use of fiat jets the air is directed well into the tire boX where it is most effective, it having been found in practice that a nozzle forming a jet, of small size can project the air only a very short distance within the combustion chamber without the use of excessive pressure differences within and without the nozzle. So far as l am aware prior devices intended for the purposes of this invention have been made of cast metal which is of considerable thickness and weight and when carried by the furnace door are clumsy and subject the doors and their mountings t-o severe strain as the doors are opened and closed. Furthermore the thickness of the walls of such cast metal devices acts to delay the conduction of heat resulting in great differences of temperature between its inner and outer surfaces so that the air is inadeqiuitely heated by the time it is admitted to the comluistitin chamber.

These difficulties have been overcome in the present invention by constructing the device of sheet steel, producing a comparatively'light weight device capable of quickly transmitting' heat to the air passing therethrough. lVhile the device becomes very hot, in practice it has been found that the Serial No. 634,666.

air passing therethrough is suflicient to prevent burning or other injury because of the high ten'iperaturc.

The device of the present invention is also so designed that little adjustment is ever necessary, and that which it is desirable to make, as when changing fuels as from hard to soft coal. may be made by simple tools by an unskilled person.

For a more complete understanding of this invention reference may be had to the :ucompanying drawings in which Figures l and 2 are perspectives of the device detached showing opposite ends thereof.

Figure 3 1s a fragmentary cross section through a domestic hot air furnace showing in section the device in operative position.

Figure 4 is a fragmentary view in perspective showing the device attached to the inner face of the tire door.

Referring to these figures it will be seen that the device comprises a sheet metal crasiug having upper and lower walls l and 2 arranged in substantially parallel spaced relation, these walls being joined at their side edges by side plates 8 which converge toward each other away from the open end 4 of the casing. The walls i. 2. and S may he made integral and formed by bending sheet material of the proper size and shape` the ends of the sheet as shown being brought together and lapped in a seam 5. At 6 is shown a reentrant angle wall forming the inner 0nd of the casing joining the side walls 3 and forming therewith and with the top and bottom walls l and 2, a pair of spaced siibstantially7 flat nozzles 7 through which heated air may pass from the interior of the casing into the combustion chamber as shown by the arrows in Figure S. This easing is designed to be made fast to the inner face of a fire door as shown at l0 in Figures 3 and 4. the fire door being provided with one or more air openings ll in the usual manner through which air may enter the casing to be heated and then projected into the combustion chamber as above noted.

Any suitable means may be provided for attaching the casing to the door, but as shown one or more bolts 12 may be employed extending from the outer face of the door and through the apex 9 of the reentrant angle wall 6 beyond which it may receive a Cil nut 13 by which the casing may be drawn back against the inner surface of the tire door. It will be noted from the drawing that the apex 9 at the rear of the reentrant angle wall 6 is positioned somewhat closetI to the lower wall 2 than to the upper wall 1. rthis causes a greater volume of air to be passed through the upper nozzle T than through the lower nozzle. The air passing through the lower nozzle as shown is directed closely against the upper face of the fuel bed so as to unite with the gases distilled off therefrom and forni therewith a combus tible mixture which is ignited by the liie. This nozzle projecting sutliciently far into the combustion chamber so that it is maintained highly heated by the combustion of the fuel so that when the air is admitted to the combustion chamber through the nozzle it is in condition to be readily ignited. The gases evolved from the fuel are thus largely consumed adjacent the surface thereof, the gases and air forming a combustible mii:- ture adjacent the surface of the fuel over a large area thereof, the air being admitted in a,si1bstantially flat sheet or layer which is able to pass well within the combustion chamber without excessive pressure due to a heavy furnace draft. T he gases and air from the lower nozzle therefore perform their function as long as any gases are evolved from the fuel and act as a pilot light to ignite gases driven olf in considerable voluine from fresh fuel when this is applied to the lire. ll'hen fresh fuel is applied these gases which escape unburned from the tield of action of the lower nozzle are broken up and thoroughly mixed with air passing through the upper nozzle 7 so that they form a combustible mixture which is immediately ignited by the flame adjacent the lower nozzle. This construction of the casing affords an extended heating surface for the nozzles and is of sheet metal of such thickness that the heat conduction is very rapid. The vdevice is also of comparatively light weight so that no severe strains are imposed on the door or its mouutings when the door is opened or closed.

lt has been found in practice that the. pipe damper employed between the check draft and the ehin'mey may be nearly closed without causing an accumulation of gas to be formed in the combustion chamber inunediately after fresh fuel is supplied which ordinarily would be liable to cause an explosion therein. The gases given otf are burned within the combustion chamber and are not permitted to escape as combustible gases or be thrown off and produce injurious fumes in the surrounding atmosphere.

lVhen fuel such as hard coal is yemployed the nozzles may be made comparatively narrow by partially closing them by the use of pliers, bringing the upper and lower walls and the reentant wall 6 at the nozzle openings comparatively near together. while when soft coal is heilig en'iployed these nozzles may be made wider Yby suitably bending the material. ln use the inner end of the casi-ng and the nozzles become very hot but it has been found that the air passing therethrough is sufficient to prevent burning or other injury to the nozzles by this eXtreme heat. As the con'iliiuetil'zle gases driven otf from the fresh fuel by the incandescent fuel th iebeneath are thus coi'isumed in the furnace, the heat derived from this combustion is utilized and the production of smoke and the throwingl otl4 of deleterious combustible gases is eliectually prevented.

Having thus described an embodiment o" this invention it should be evident to those skilled in the art that many changes and modilications might be lnade therein without departing from its spirit or scope as defined by the appended claims.

l claim:

l. A device of the class described coinprising a casing for attachment at its open outer end to the inner face of a tire door,said casing having substantially horizontal upper and lower walls, side walls, and an inner end wall formed as a reentrant angle portion joining said side walls and forming therewith and with said upper and lower walls a pair of horizontally disposed fiat nozzle openings.

A, device of the class described coinprisingr a casing for attachment at its open outer end to the inner face of a tire door, said casing having substantially parallel upper and lower walls`r converging side walls, and an inner end wall formed as a rzeentrant angle portion joining said side walls and forming therewith and with said upper and lower walls a pair of horizontally disposed flat nozzle openings, the apex of said reentrant angle portion being closer to said lower than to said uppcr wall to cause a larger proportion of air entering said casing through said door to escape through said upper nozzle.

3. A device of the class described coluprising a casing for attachment at its open outer' end to the inner face of a tire door, said casing having substantially parallel upper and lower walls. converging side walls, and an inner end wall formed as a reentrant angle portion joining` said side walls and forming` with said upper and lower walls a pair of horizontally disposed flat nozzle openings, and means passing through the apex of said reentrant angle portion for attaching said casing to said door.

Al. A device of the class described comprising a sheet metal casing having substantiallv parallel upper and lower walls, side walls joining said upper and lower walls and converging toward one end therei Ut) of, a reentrant angle end wall positioned between said side walls at said converging end and spaced from said upper and lower walls to define therewith a pair of spaced horizontally disposed narrow slots through said end, and means for fixing said casing with its opposite open end against the inner face of a furnace door.

A device of the class described conv prising a sheet metal casing having substantially parallel upper and lower walls. side walls joining said upper and lower walls and converging toward one end thereof, a reentraut angle end wall positioned between said side walls at said converging end and spaced from Said upper and lower walls to define therewith a pair of spaced horizontally disposed narrow slots through said end, said reentrant angle portion being closer to said lower than to said upper wall and means for fixing said casing with its opposite open end against the inner face of a furnace door.

6. The combination with a furnace having a combustion chamber, and a door for closing an opening into said chamber through which fuel may be supplied thereto. said door having openings therethrough, of a casing having upper and lower and side walls and an inner end wall formed with a reentrant angle and defining with said upper, lower and side walls a pair of spaced nozzles, and means engaging the rcent nant angle portion of said end wall and said door for fixing said casing to said door with the outer edges of said upper, lower and side walls against the inner face of said door and enclosing said door openings.

ln testimon)v whereof l have affixed my signature.

WILLIAM M. HAYWARD. 

